The provisions of the Act regulated the design of new buildings erected in London and elsewhere in Great Britain and Ireland in the late Georgian period.

The Act also brought into being the first legislation that dealt with human life and escape, rather than just building safety, and made parishes responsible for permanent provision of working fire fighting equipment.

Professor Sir John Summerson, one of the leading British architectural historians of the 20th century, described it as "the great Building Act of 1774, a milestone in the history of London 'improvement'".

[1] It was the leading reason for the appearance of the many Georgian houses, terraces and squares which remain important features of some parts of London and other cities and towns within the United Kingdom, the Republic of Ireland and elsewhere.

[Note 1] Its aims included:[1] The Bill was submitted to the House of Commons in February 1774 by Robert Taylor and James Adam as "Joint Architects to H. M. Works", "on behalf of the Builders of London and Westminster", who found the existing legislation confusing and out of date.

[9][10] In order to lay down hard and fast, standardised rules of construction it was necessary to categorise London buildings into separate classes or "rates".

Window joinery which previous legislation had already pushed back from the wall face was now concealed in recesses to avoid the spread of fire.

[19] A builder-speculator bought the leasehold of a site from the ground landlord and built the shell and roofed and floored it, usually with the bare internal walls roughly plastered out.

[23] By far the greatest number of speculative houses built were of the third rate, whose exact dimensions were arrived at as a result of the areas defined in the Act.

[25] Many of the regulations of the Act were subsequently applied outside of London in other cities and towns of Great Britain, especially in Bristol[26] and Liverpool,[27] and were also influential in developments in Edinburgh, Bath, Tunbridge Wells, Weymouth, Brighton, Margate, Buxton, Warwick, Newcastle upon Tyne and Cheltenham, and in Dublin and Newtown Pery in Ireland.

[34] Benjamin Disraeli blamed the Act for "all those flat, dull spiritless streets all resembling each other, like a large family of plain children.

"Gower Street in Bloomsbury, for example, was described by The Builder journal in 1887 as "one of the dullest, gloomiest thoroughfares in town [with its] monotonous elevations wholly unbroken or unrelieved",[37] and was referred to a decade later by historian Sir Laurence Gomme, in his commentary on London in the Reign of Victoria, as a "hideous monstrosity".

[38] The Victorians often did their best to destroy the scale and symmetry which were the hallmark of the Act, by breaking up the line of Georgian frontages and adorning their immaculate façades with terracotta and composition dressings.

This was, in many ways, an excellent thing: it gave some degree of order and dignity to the later suburbs and incidentally laid down minimum standards for working-class urban housing which would have been decent if they had been accompanied by legislation against overcrowding.

"The Act moved London away from its earlier chaotic and often mediaeval conditions, and ensured that whole city would be decent, handsome and orderly.

It meant that, in an era when almost all construction was undertaken on speculative building leases, the landowner, the tenant and the community at large had a real guarantee of quality.

It has been suggested that, by imposing a uniform image and a means to identify and control London before its subsequent immense expansion, the Act prepared the capital for its next imperial phase.

The new rating system led to the development of what are today perceived as grand and gorgeous terraces and squares in London and other cities and towns, creating simple and elegant uniformity which is much admired and reflected in the premiums paid when purchasing a Georgian property.